Star Trek: 10 Disturbing Side Character Backstories

Star Trek: Discovery taught us a lot about the life of Sarek, Spock's father. We learned that when Michael Burnham's parents were killed, during the bombing of the learning centre by logic extremists, Sarek and his Human wife Amanda Grayson adopted Burnham and raised her in the Vulcan way alongside Spock, their half-Vulcan, half-Human son. Both Spock and Burnham were extensions of Sarek's work to bolster the relationship between Humans and Vulcans.

It was Sarek's goal to have both Spock and Burnham attend the Vulcan Science Academy, but we see in the episode Lethe that the Academy, unwilling to have two members with Human heritage, made Sarek choose which of his children he wanted to be accepted. Sarek chose Spock, a decision that he regretted his whole life, and hid from Burnham until she revealed it during a form of long-distance mind meld.

Sarek's guilt was made even worse when Spock chose to leave the Vulcan Science Academy to join Starfleet. After this point, his relationships with his children worsened more and more until he barely talked to them anymore. And this was all after Sarek's first son Sybok had already fled Vulcan.